Apparatus and method for down-regulating immune system mediators in blood

ABSTRACT

A method and apparatus for preventing and treating septicemia in patient blood is provided. The extracorporeal system includes an antimicrobial device to inactivate at least 99% of bloodborne microorganisms, a hemoconcentrator/filtration unit to remove approximately 50-75% of target molecules from the patient blood and a filter unit to remove target molecules from patient blood from the sieved plasma filtrate. Target molecules are produced by microorganisms, as well as by the patient&#39;s cells. These molecules include endotoxins from Gram negative bacteria, exotoxins from Gram negative and Gram positive bacteria, as well as RAP protein mediator from  Staphylococcus aureus,  and cell mediators such as tumor necrosis factor-alpha, and interleukin 1-beta, interleukin 6, complement proteins C3a and C5a, and bradykinin.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to methods and apparatusfor inactivating bloodborne microorganisms. This invention relates tomethods and apparatus for removing target molecules from the blood by ahemoconcentrator/filter and for subsequently removing target moleculesfrom the ultrafiltrate by additional filtration for endotoxins and cellmediators before returning the treated blood to the patient. Ultravioletirradiation is used in some aspects of the invention.

[0003] 2. Description of the Related Art

[0004] Septicemia refers to a microbe-induced condition in which thepatient experiences an exaggerated inflammatory response. This responsecan lead to varying degrees of hypotension (possibly shock), andhypoxemic and edema-related organ failure called multiple organdysfunction syndrome (MODS). Because trauma and burns, among othercauses, can lead to MODS, in the absence of infection, the more currentand generic term is systemic inflammatory response syndrome (SIRS).

[0005] Between 1980 and 1992 the death rate due to septicemia increased83% from 4.2 to 7.7 per 100,000 population. The greatest increases wereseen in patients at least 65 years old. Bacterial infections accountedfor approximately 200,000-300,000 cases of septicemia as of 1992, andwas the thirteenth leading cause of death nationally. In 1992, themortality rate averaged 35%, with a range of 20-65%, and accounted forapproximately 100,000 deaths. Now, the average mortality rate hasincreased to about 200,000 deaths per year, and is the tenth leadingcause of death in the United States. There are now 1.5 million cases ofsepsis worldwide. This number is expected to increase to 2.2 million inthe next ten years.

[0006] Septicemia is usually categorized by the particular group ofmicroorganism involved, i.e., bacterial, Gram negative or Gram positive,and fungal. Gram negative bacteria of concern include Pseudomonasaeruginosa, Eschericia coli, and Enterobacter aerogenes. Gram positivebacteria of interest include Staphylococcus aureus, Streptococcuspneumoniae, and Enterococcus spp. The usual fungus involved is theyeast, Candida spp. Septicemia and related conditions develop whencertain microorganisms, the cellular products, and other targetmolecules stimulate cascade reaction and an exaggerated inflammatoryresponse leading to multiple organ and system failure. Selectedmicrobial products and other target molecules, with molecular weights,are shown in Table 1. TABLE 1 Pro-Inflammatory Anti-InflammatoryMediators Size Mediators Size IL-1β 17 kD IL-1ra 25 kD IL-6 26 kDIL-1RtypeII 68 kD TNF-α 17-54 kD IL-4 15 kD IL-2 15 kD IL-10 40 kD IL-1244 kD IL-13 10 kD IL-8 8 kD C3a 8 kD C5a 9 kD LBP 55 kD MIF 12 kD IFN 17kD LIF 20 kD VCAM 80 kD ICAM-1 90 kD LPS 10-100 kD

[0007] These target molecules may enhance the microbe's virulence and/orstimulate the patient's defense mechanisms, but, when excessive, theymay lead to multiple organ system failure. These microorganisms, theircellular products and the target molecules can stimulate various cascadereactions which may result in a life-threatening inflammatory diseasestate.

[0008] Prevention of these medical conditions is difficult at bestbecause the early signs and symptoms may be quite vague. Treatment hasgenerally been instituted when the condition is recognized which is,unfortunately, often very late in the course of the disease. Withprophylaxis difficult and therapy often late, the results may be fatalfor the patients in many cases.

[0009] Ultraviolet blood irradiation, originally the Knott technique,has been used in the United States since 1928 for the successfulextracorporeal treatment of microbial infections. Over the years therehave been scientific arguments concerning the mechanism by whichultraviolet blood irradiation (“UBI”) works, and the consensus appearsto be that some organisms are inactivated. It is believed that UV lightradiation of range “C”, or UV-C, stimulates the immune system to becomemore efficient at clearing the remaining organisms from the body.

[0010] Hemoconcentrator/filtration units are used to remove water frompatients who are in acute renal failure and become overly hydrated. Thedevices are designed to retain the majority of plasma proteins,including one of the smallest, albumin, (molecular weight of 67-69 kD),while ridding the blood of excess water. Current membranes and/or hollowfiber systems have effective pore sizes which will pass molecules up to30-50 kD.

SUMMARY OF THE INVENTION

[0011] It is one object of the present invention to provide a bloodtreatment system to inactivate bloodborne microorganisms. In one aspect,a method and apparatus is provided for removing target molecules fromthe blood by a hemoconcentrator/filter and for subsequently removingtarget molecules from the ultrafiltrate by additional filtration forendotoxins and cell mediators before returning the treated blood to thepatient. Ultraviolet irradiation is used in some aspects of theinvention.

[0012] It is one object of the present invention to remove blood from apatient, or obtain blood from a source, and to provide a diluent sourcefor supplying a diluent to reduce the hematocrit of the blood. In oneaspect, the diluent source supplies a diluent which reduces the blood toa hematocrit of about 5% to about 20%. A concentrator device to receiveblood is provided to filter the blood and to remove the diluent. Areturn path connected for returning filtered blood from saidconcentrator device to a blood source. In one aspect, the return pathincludes tubing and/or a single lumen cannula.

[0013] It is another object to provide a recycle path connected forreturning the diluent removed from the blood by the concentrator deviceto said diluent source. In one embodiment, the recycle path comprises afilter. In one aspect, the recycle path includes a membrane moduleand/or a recycle pump.

[0014] It is one object of the invention to provide a filter deviceconnected to receive blood from the source and to supply a portion ofthe blood to an irradiator or to another filter and to return theremainder of the received blood to the source. It is a further object toprovide a reservoir connected to receive material filtered from theblood by the concentrator device.

[0015] It is a further object to provide a system and method to treatblood using two types of filters. In one embodiment, the first filter isa hemoconcentrator filter having a porosity of about 70-90 kilodaltons.In one aspect, the first filter is made of polysulfone fibers. Thesecond filter is a cytokine filter having a porosity of about 10-30kilodaltons. In one aspect, the second filter includes two filtersconnected in parallel, each filter having a porosity of about 10-30kilodaltons. In one embodiment, the second filter has a porosity ofabout 10 kilodaltons.

[0016] In one aspect of the invention, the concentrator device has amembrane or filter having a transmembrane pressure greater than 76 mmHg.In one aspect, the concentrator device includes two hemoconcentratorsconnected in series. In some aspects, each hemoconcentrator is connectedto a separate hemoconcentrator pump. In one aspect, the concentratordevice filters the blood received thereby by the size of theconstituents of the blood. In one embodiment, the concentrator deviceincludes a hollow cylinder and a central core formed of hollow fibersaxially disposed within the hollow cylinder. In one aspect, the hollowcylinder has a length of about 10 inches and a diameter of about 1.5inches, and the central core has a surface area in the range of betweenabout 1.2 m² to about 2.4 m². It is one object of the present inventionto provide an inlet monitoring means at the concentrator device formonitoring the pressure of the blood.

[0017] It is one object of the current invention to provide a system andmethod for treating blood using a device having a concentrator or firstfilter that has a transmembrane pressure (TMP) that is greater than 76mmHg. The range of TMP is as follows: about 80 mmHg to about 85 mmHg,about 86 mmHg to about 95 mmHg, about 96 mmHg to about 105 mmHg, andgreater than about 105 mmHg.

[0018] It is yet another object of the invention to provide at least onepump connected to said system for moving blood, diluent or other fluidthrough the system. In another aspect of the invention, the combinedblood/diluent flow rate is less than 400 ml/min. The range of thecombined flow rate is as follows: about 75 ml/min to about 125 ml/min,about 126 ml/min to about 200 ml/min, about 201 ml/min to about 300ml/min and about 301 ml/min to 400 ml/min. In one aspect, the blood flowrate alone is about 50 ml/min to about 300 ml/min, preferably about 100ml/min.

[0019] It is another object of the invention to provide an oxygenatorconnected between the source and said filter device in order tooxygenate the blood received from the source.

[0020] It is a further object to provide a heater to warm at least aportion of the blood or a heat exchanger to cool at least a portion ofthe blood. In one embodiment, blood is heated or cooled by about 1-10°C.

[0021] It is one object of the current invention to further provide a UVirradiation device to irradiate blood. In one aspect, the UV irradiationdevice receives and irradiates blood containing biological toxins from asource of blood. In one embodiment, the irradiator device includes a UVlight source and a fluid chamber adjacent to the UV light source, wherethe fluid chamber confines the fluid to a thin film for exposure to theUV light source. In one aspect, the UV light source delivers ultravioletradiation to the blood in a dose ranging from about 2 mW/cm² to about 20mW/cm². In another aspect, the effective dose of ultraviolet radiationapplied to the blood is about 1 mW/cm² to about 19 mW/cm². In oneaspect, the fluid chamber is a bag for holding the diluted blood, thebag having a length in the range of about 15 inches to about 20 inches,a width in the range of about 8 inches to about 10 inches, and a fluidpath having a width of about 0.75 inches to about 1 inch. In one aspect,a sensor is provided to monitor ultraviolet radiation emitted by theirradiator device.

[0022] It is one object of the invention to provide a system and methodto treat a patient having an inflammatory disease. Inflammatory diseasesinclude, but are not limited to, sepsis, acute renal failure, ischemicstroke, Sudeck's syndrome, chronic fatigue syndrome, heat stroke,Hodgkin's Disease, lupus, myocardial infarction, AIDS, viremia, HCV,HBV, tuberculosis, muscular dystrophy or multiple sclerosis, AcuteRespiratory Distress Syndrome, and heart disease.

[0023] It is yet another object of the invention to provide a system andmethod of reducing free radicals in a patient's blood. In oneembodiment, one or more free radical quenchers are added to the bloodprior to, during and/or after treatment with the concentrator/filterembodiments described herein. Quenchers are administered directly to thepatient and/or are added to the various components of theconcentrator/filter embodiments, including, but not limited to, thetubing, the pump, the filters and the diluent source so that the bloodcan be exposes to the quenchers while being concentrated or filtered. Inone embodiment, the quencher is an antioxidant. Quenchers used inseveral embodiments of the present invention include, but are notlimited to, Zn, Cu, manganese, selenium, vitamin A, C, E, B complex, K,P, lycopene, superoxide dismutase, co-enzyme Q10, catechins,polyphenols, flavanols, depsides (chlorogenic acid, coumaroylquinic acidor theogallin), quinic acids, carotenoids, thearubigens, theaflavin,theaflavic acids and ethyl pyruvate. In one embodiment, a cocktail ofvitamin A, vitamin C, vitamin E and zinc is used. Quenchers are providedin a dose sufficient to reduce the concentration of one or more freeradicals in the blood.

[0024] It is a further object of the instant invention to provide asystem and method of reducing toxins in a patient's blood using vitamintherapy. These vitamins include the free radical quenchers andantioxidants described above, and include several vitamins which exerttheir action by reducing the concentration of toxins, including, but notlimited to bacteria, viruses, free radicals and inflammatory mediators,in the blood. In one embodiment, vitamins are added to the blood priorto, during and/or after treatment with the concentrator/filterembodiments described herein. Vitamins are administered directly to thepatient and/or are added to the various components of theconcentrator/filter embodiments, including, but not limited to, thetubing, the pump, the filters and the diluent source so that the bloodcan be exposed to the vitamins while being concentrated or filteredusing this system.

[0025] It is another object to provide a system and method of treatingblood by using a hemoconcentrator/filter system in conjunction withadministering a drug in a dose sufficient to facilitate cellular glucoseentry. In one embodiment, insulin therapy is provide to regulate glucoselevels.

[0026] It is a further object to provide a system and method of treatingblood by using a hemoconcentrator/filter system in conjunction withadministering a drug in a dose sufficient to facilitate microcirculationand organ oxygenation. In one embodiment, nitroglycerin is provided tothe patient to increase microcirculation.

[0027] It is yet another object to provide a system and method ofdown-regulating a patient's immune system by removing one or more immunesystem mediators from the patient's blood. In one embodiment, blood isobtained from a patient and diluted to reduce the hematocrit of theblood. The diluted blood is then filtered to reduce concentration of atleast one immune system mediators from the diluted blood. The blood isalso concentrated to remove the diluent from the blood. The treatedblood is then reintroduced into the patient. Because one or more immunesystem mediators is removed from the treated blood, the patient's immunesystem is down-regulated. In one aspect, the immune system mediator isan inflammatory mediator. In one embodiment, the concentration of atleast one inflammatory mediator is reduced by about 75% in less thanabout 4 hours. In one embodiment, the concentration of TNF-α is reducedby about 50% in less than about 4 hours. Inflammatory mediator include,but are not limited to, TNF-α, IL-1β, IL-6, IL-8, IL-10, IL-12, LPB,IFNγ, LIF, MIF, MCP-1, C3-a, C5-a, exotoxins and endotoxins. In someembodiments, the immune system is down-regulated using a transmembranepressure greater than 76 mmHg. In another embodiment, a flow rate ofless than 40 ml/min is used. Filter and hemoconcentrators, describedabove, are used to down-regulate the immune system in many embodiments.In several embodiments, irradiation, free radical quenchers, vitamintherapy, insulin therapy and/or nitroglycerin, as described herein, areused in conjunction with or to facilitate immune system down-regulation.

[0028] It is yet another object of the present invention to provide adevice for treating blood using three pumps, a blood pump, a diluentpump and a hemoconcentrator pump. In this embodiment, referred to as“the HemaCharge device,” a load cell to maintain proper hemodilution andhemoconcentration of patient blood is provided. The user interface is abacklit LCD touch screen display. The device also incorporates clamps, abubble detector, pressure sensors, temperature sensors, a UV sensor, aswell as visual and audible alarms for patient safety. Also provided is apower supply module containing an isolation transformer, a solid-stateelectronic ballast, and associated electronics to produce about 5-24 VDCto power the pumps, clamps, and sensors. A strain gauge beam type loadcell is provided to measure the weight of the diluent bag. A 70-90 kDpolysulfone hollow fiber filter used for hemoconcentrating dilute bloodand two 10 kD polysulfone hollow fiber filters for cytokine removal arealso provided. An ultraviolet irradiator lamp assembly is also provded.The UV irradiator assembly is used to irradiate dilute extracorporealblood with 254 nm UV-C energy. The assembly comprises a 200 W UVC gridlamp and lamp support structure, two quartz glass plates and compressionplates to constrain the diluted blood in the irradiator bag toapproximately 0.025″ thickness. UV-C and temperature sensors are used tooptimize ultraviolet output of the bulb. A safety interlock switch isprovided to prevent unwanted user exposure to UV-C whenloading/unloading the disposable set of materials. Five pressure sensorsare used; one each on the patient inlet and return lines, one before theirradiator bag assembly inlet, one at the hemoconcentrator inlet, andone located between the hemoconcentrator ultrafiltrate outlet and theconcentrator pump. The inlet pressure sensor can be used to determinemaximum allowable blood flow rate based on vascular access and catheterplacement parameters; the patient return line sensor can likewiseindicate catheter placement issues on the return side, as well asprovide a measure of safety against excessive return pressures. Thesensor located before the irradiator bag assembly provides an indicationof bag pressure and is used to prevent over pressurization of theirradiator bags. The sensors located at the inlet and ultrafiltrateoutlet of the hemoconcentrator as well as the patient return sensor areused to determine hemoconcentrator TMP. TMP is used to determineappropriate blood flow rates and to determine adequate performance ofthe hemoconcentrator. Visual and audible alarms are provided forout-of-range pressures.

[0029] It is another object of the present invention to provided manualand/or automated mechanisms of control for several embodiments describedherein. In one embodiment, on-line pressure monitors or optical devicesaid a technician in regulating hematocrit. In other embodiments,monitoring and regulation of hematocrit is automated using an electronicweight scale, or load cell, which measures the volume or mass ofdiluent. Computer hardware and software is also used in variousembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a schematic representation of one embodiment of thesystem of the instant invention.

[0031]FIG. 2 shows a schematic of one embodiment of the UV irradiatorand bag.

[0032]FIGS. 3A-3E show various views of one embodiment of the UV system.

[0033]FIG. 4 shows the irradiator bag in open position.

[0034]FIG. 5 shows the irradiator bag in closed position.

[0035]FIG. 6 shows the irradiator in open position.

[0036]FIG. 7 shows UV-C penetration as a function of blood thickness.

[0037]FIG. 8 shows dilutional effect on bacterial reduction in vitro.

[0038]FIG. 9 shows bacterial reduction data at various hematocrits.

[0039]FIG. 10 shows bacterial reduction data at 30% hematocrit.

[0040]FIG. 11 shows cytokine sieving/reduction data in vitro.

[0041]FIG. 12 shows a hardware/software scheme used in severalembodiments of the invention.

[0042]FIG. 13 shows a physical embodiment of the HemaCharge System.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0043]FIG. 1 shows a schematic representation of one embodiment of thepresent invention. In one embodiment, blood is pumped from the patient100 at a flow rate of about 100-300 ml/min, using a blood pump 102. Oneof skill in the art will understand that blood can also be pumped at aflow rate less than about 50 ml/min and at a rate greater than about 300ml/min. A blood flow rate of less than about 50 ml/min may lead toclotting in certain cases. A blood flow rate of greater than 300 ml/minmay not be supported by certain hypovolemic and/or hypotensive patientsand may lead to venous stenosis or collapse.

[0044] Blood is diluted using diluent pump 114 to adjust the hematocritto about 10%, and then circulated into a bag within the UV irradiator104. The irradiated blood then flows towards the 70-90 kD filter 106,which removes an ultrafiltrate containing molecules less than about 90kD in weight. Through removal of the ultrafiltrate, the cellular bloodelements are restored to their original concentration before returningthe blood to the patient. The ultrafiltrate is pumped through a 10 kDfilter 112 using a hemoconcentrator pump 110, where molecules greaterthan about 10 kD are retained, and those less than about 10 kD areallowed to pass through and into the diluent source or reservoir 113where they become available for mixing with blood that is being removedfrom the patient. At the end of the approximately 3-hour procedure, muchof the whole blood extracorporeal volume is returned to the patient 100in an attempt to preserve total red cell volume.

[0045] Because most pro-inflammatory/anti-inflammatory mediators have amolecular weight of 10 to 90 kD, it is expected that about 50-75% ofimmune system mediators will be removed from blood after about 3 hoursof treatment. In several embodiments, reduction of target molecules isaccompanied by substantial irradiation-induced bacterial reduction. Inone embodiment, the TNF-α trimer, the principal form in blood with amolecular weight of about 45-55 kD, will be removed by this method.

[0046] In one embodiment of the present invention, a system to reducebacterial load in septic patients is provided. Diagnosis and preventionof septicemia and related conditions is difficult because the earlysigns and symptoms are usually vague. Because these conditions aretypically recognized late in the course of the disease, morbidity andmortality rates are unduly increased. In one embodiment, bacterial loadis reduced by about 99%. In several aspects of this invention,septicemia is prevented or treated in patients undergoing coronarybypass, dialysis and other conditions. In one embodiment, the systemdisclosed herein can be used to prevent or treat septicemia in patientsundergoing any invasive procedure. In several embodiments, the devicedescribed herein can prevent and/or treat systemic inflammatory responsesyndrome by any etiology, including, but not limited to septicemia ormicrobial sepsis. In one embodiment, patients with acute renal failurecan be treated. In another embodiment, patients with ischemic stroke canbe treated.

[0047] In one embodiment of the invention, a prevention and treatmentsystem for Sudeck's Syndrome is provided. Sudeck's Syndrome, also knownas Reflex Sympathetic Dystrophy, is characterized by acute atrophy ofbones, commonly of the carpal or tarsal bones. Biochemical mediators andan excessive inflammatory reaction are involved in the etiology andprogression of this disease. (Cook and Ward, 1990; Goris, 1998, bothherein incorporated by reference). In one embodiment, ahemoconcentrator/filter system is used to remove target molecules fromthe blood of a patient afflicted with Sudeck's Syndrome. Moleculestargeted for removal include, but are not limited to, prostaglandins,endothelium-derived relaxing factor and histamine. One skilled in theart will understand that other cell mediators involved in this syndromecan also be removed in accordance with several embodiments of thepresent invention.

[0048] In a related embodiment, a hemoconcentrator/filter system is usedto remove target molecules from the blood of a patient afflicted withChronic Fatigue Syndrome. Molecules targeted for removal include, butare not limited to, TNF-α, IL-6 and other cytokines. One skilled in theart will appreciate that other cell mediators involved in ChronicFatigue Syndrome can also be removed in accordance with severalembodiments of the present invention.

[0049] In addition to removing tumor necrosis factor, or TNF-α, frompatients with Chronic Fatigue Syndrome, other embodiments of the presentinvention provide a system for reducing TNF-α levels, and/or otherimmune system mediators, in any illness in which these mediators areinvolved in the etiology or progression of the disease.

[0050] In other embodiments, a prevention and treatment system for otherinflammatory related diseases is provided. These diseases include, butare not limited to, heat stroke, Hodgkin's Disease, lupus, myocardialinfarction, AIDS, viremia, HCV, HBV, tuberculosis, muscular dystrophy ormultiple sclerosis, Acute Respiratory Distress Syndrome (ARDS), andheart disease.

[0051] Transmembrane Pressure (TMP)

[0052] Hemoconcentrator transmembrane Pressure (TMP) is calculated as(Inlet Pressure+Outlet Pressure/2)−Ultrafiltration Pressure. In apreferred embodiment, TMP is kept below about 400 mmHg for maximumfilter performance. Exceeding this maximum TMP may result in filterfailure (i.e., a clogged filter) which could potentially send clots backto the patient. However, one skilled in the art will appreciate thatunder certain conditions, a TMP greater than about 400 mmHg can be used.The range of TMP used in one embodiment of this system is about 1-400mmHg. TMP typically depends on factors such as entering HCT, exiting HCTand blood flow rate. In one embodiment, the TMP is between about 1-200mmHg, preferably between about 9-105 mmHg. Typically, at a constant flowrate, a decrease in hematocrit results in a lesser pressure drop andlower inlet pressure, while an increase in hematocrit results in agreater pressure drop and higher inlet pressure. Thus, changes in inletpressure signal changes in hematocrit. Thus, in one embodiment, on-linepressure monitors or optical devices can aid a technician in regulatinghematocrit. In other embodiments, monitoring and regulation ofhematocrit is automated using a load cell, described below.

[0053] In U. S. Pat. No. 6,193,681, we described a method and apparatusfor inactivating bloodborne microorganisms by ultraviolet irradiation.In that system, the pressure across the hemoconcentrator was designed todecrease 70-100 mmHg from inlet port to outlet port. The TMP of theoriginal system was about 50-75 mmHg. In the present invention, a designin which the pressure across the hemoconcentrator decreases 1-69 mmHgand in which the TMP is greater than about 76 mmHg provided surprisingand unexpected advantages. For example, hemoconcentration was achievedmore efficiently allowing a higher flux rate which translates intogreater target molecule sieving. More importantly, using a TMP greaterthan about 76 mmHg and a blood flow rate of about 100 ml/min allowsprocessing of blood with a hematocrit of greater than about 36%. Thesystem disclosed in U.S. Pat. No. 6,193,681 was able to process bloodhaving a hematocrit less than about 35%. Embodiments of the currentinvention are particularly advantageous because it is estimated thatover 20% of septic patients have a hematocrit that exceeds 35%.Moreover, a system which uses a TMP greater than 76 mmHg also provides anovel and unique method of treating several other disorders in whichhematocrit exceeds 35%. In particular, about 50% of patients with renalfailure, 99% of stroke patients and 99% of patients with autoimmunedisorders have blood hematocrit levels that are greater than 35%. Thesepatients would greatly benefit from a system which was capable ofinactivating life-threatening microorganisms in their bloodstream.Embodiments of the current system, which use a TMP of greater than about76 mmHg, offers this treatment opportunity to these patients. Indeed,using a TMP that is greater than 76 mmHg with a blood flow rate that isgreater than 100 ml/min allows treatment of septic patients that have ahematocrit less than 36%.

[0054] In one embodiment, the TMP of the present invention is greaterthan 76 mmHg, preferably from about 76-150 mmHg, and more preferablyfrom about 76-105 mmHg. TMP ranges from about 76-85 mmHg, 86-95 mmHg and96-105 mmHg are also provided in accordance with several embodiments ofthe current invention. As discussed above, a TMP greater than 76 mmHgcorresponds to a hematocrit greater than about 36%, a value whichrepresents 20% of septic patients and a large percentage of otherpatient populations. In one embodiment, blood having a hematocrit ofgreater than 36% is treated. Hematocrit ranges from about 36% to about40%, 41% to about 50%, 51% to about 55%, and greater than about 55% arealso provided in accordance with several embodiments of the currentinvention. Ideally, blood treatment provided in several embodiments ofthe present invention will last about 1-3 hours. However, in analternate embodiment, a longer treatment can be performed at a slowerblood flow rate. This embodiment has particular benefits to ahemodynamically unstable patient. In one embodiment, this system uses aTMP of less than about 50 mmHg and takes more than about 3 hours toaccomplish the toxin removal goals.

[0055] System Operation—Blood Pump

[0056] Blood is received from the patient through a canula placed in thefemoral subclavian or internal jugular vein. One skilled in the art willunderstand that other methods used to withdraw blood from a patient canalso be used in accordance with several embodiments of the presentinvention. In one embodiment, a filter device is connected to receiveblood from the source and to supply a portion of the received blood to aUV irradiation device and to return the remainder of the received bloodto the source. In one embodiment, a canula is connected to a patient anda tubing is connected to the canula through a pump and into a hollowfiber filter device to receive blood from the source. The pump suppliesa portion of the blood to the irradiation device or the concentrator andreturns the remainder of the blood back to the patient. In anotherembodiment of the invention, blood is received from a source. The sourceincludes, but is not limited to, blood that has been previouslywithdrawn from a patient and stored. The source also includes donatedblood taken from one or more healthy individuals, which requirestreatment before being available as a donor blood.

[0057] When receiving blood from the patient, a blood pump controls theflow rate of the blood in several embodiments. A preferred embodiment ofthe present invention has three pumps. As shown in FIG. 1, oneembodiment has a blood pump 102, a diluent pump 114, and a concentratorpump 110. In one embodiment, blood from pump 102 passes through apolycarbonate “Y” connector where the blood mixes with a suitableisotonic diluent, such as Plasmalyte™ solution. A variety of suchsolutions, referred to as “crystalloids”, are available. The diluent issupplied from diluent source 113 which, typically, comprises a largecapacity reservoir for storing an admixture of reclaimed (or converted)ultrafiltrate. The diluent is delivered by pump 114, which can be aroller pump or the like, at a flow rate which results in a hematocrit ofabout 5-20%.

[0058] In U. S. Pat. No. 6,193,681, we described a method and apparatusin which the combined blood/diluent pump flow rate was 400-500 ml/min.In several embodiments of the present invention, a design in which thecombined pump flow rate is less than 400 ml/min provides unexpectedadvantages over a flow of greater than 400 ml/min. Surprisingly, theslower combined flow rate is safer and easier to manage on a patient andthere is a lower probability of developing cavitation from the bloodsource catheter (i..e. the arterial catheter). Additionally, greaterblood dilution results in a lower protein concentration throughout thesystem. A higher filtration fraction (filtration fraction=ultrafiltationrate/combined flow rate) results in a higher ultrafiltration (UF)/fluxrate. Less protein in the blood solution results in less proteindeposition on the surface of the hemoconcentrator. This, in turn, helpsretain the integrity of the hemoconcentrator's pore size allowing formore consistent removal of target molecules for longer periods of time.Concurrently, the greater blood dilution allows for increased UF rates,which in turn increase target molecule sieving.

[0059] In one embodiment of the present invention, the combinedblood/diluent pump flow rate is less than about 400 ml/min, preferablyfrom about 10 ml/min to about 390 ml/min, more preferably from about 200ml/min to about 380 ml/min. In one embodiment, when using a blood flowrate of about 100 ml/min, the combined blood/diluent flow rate is about280-380 ml/min.

[0060] In one embodiment of the present invention, the ultrafiltrateside of the system is a continuous length of tubing that runs through apump into a secondary filter. One of skill in the art will understandthat material filtered from the blood can be collected in a filtratecollection reservoir in a “closed-loop” system, as described in U.S.Pat. No. 6,193,681, herein incorporated by reference.

[0061] System Operation—Diluent Pump

[0062] In one embodiment, the concentrator pump 114 propels theadmixture of crystalloid and filtrate from the secondary circuit back tothe primary circuit via Y-connector. Thus, smaller molecules can beconserved by passage thereof completely through the secondary circuit,while plasma proteins and other large molecules are conserved byretention thereof in the primary circuit at the hemoconcentrator.

[0063] Pump flow is initially based on the hematocrit of the patient 100and can regulated with knowledge of hemoconcentrator inlet pressure asdetermined by an inlet port. That is, a port may include a stopcock formonitoring the inlet pressure and/or for sampling of the fluid. In oneembodiment, connection of the components in the secondary circuit is bytubing. One skilled in the art will understand that other connectormechanisms can also be used in accordance with several embodiments ofthe current invention. In other embodiments, blood pump flow is fixed atabout 100 ml/min. In yet another embodiment, the blood pump flow islowered below 100 ml/min to accommodate hemodynamically unstablepatients. In another embodiment, pump flow is regulated using TMPmeasurements. Blood flow can be monitored manually or via an automatedfeedback system, based upon TMP values.

[0064] In one embodiment of the present invention, only two pumps areused, a combined blood/diluent pump and a concentrator pump. A separateblood pump is not used. A single pump positioned substantially as pump102 shown in FIG. 1, regulates both patient blood and diluent flows. Apump with the capability of dual raceway control or a traditional singleraceway pump coupled with thumb screw control of diluent flow can beused. In the latter case, the “dual” pump flow would be regulated at aflow rate of about 100-1,000 ml/min, accounting for the combined flowsfrom the patient 100 and the diluent reservoir. 113.

[0065] System Operation—Concentrator Pump

[0066] A concentrator pump 110 is shown in FIG. 1. In one embodiment,pump 110 propels blood to a second filter 112. The target molecules aretrapped by this second filter 112 with a porosity of about 10-30 kD. Forexample, endotoxins from the cell wall of bacteria containing proteinand negatively-charged lipopolysaccharide (LPS) with a molecular weightof about 10-100 kD are captured in filter 112. In one embodiment, about99% or more of such material is captured. In one embodiment, plasmahemoglobin and myoglobin are also trapped by this filter. In yet anotherembodiment of this system, the majority of molecules with a molecularweight of less than about 10-30 kD pass through module 112 to thelarge-capacity diluent reservoir 113 where they mix with crystalloid.

[0067] In one embodiment, ultrafiltration occurs in the hemoconcentrator106 at the pressure drop previously indicated much as it does in theglomerular units of the natural kidney. However, the natural kidneyprevents the passage of the small and plentiful plasma protein albumin(67-69 kD molecular weight) and permits occasional passage of freeplasma hemoglobin (64 kD molecular weight), thereby demonstrating asharp cutoff at a molecular weight of about 65 kD. In one embodiment,the hemoconcentrator 106, with 60-95 kD porosity, is effective atprohibiting passage of plasma proteins (less than about 5% of plasmaalbumin, less than about 2% of plasma globulin sieved) while permittingsufficient passage of electrolytes, BUN, creatinine, myoglobin andglucose to ensure normal plasma osmolality.

[0068] In one embodiment, larger molecules, such as plasma hemoglobin,are incompletely sieved (about 25-95% of plasma concentrations).Permeability of target molecules IL-1β, IL-6 and some LPS is about 100%(appearing in the ultrafiltrate in concentrations equivalent to plasma)in one embodiment of this system. TNF-α, with a molecular weight of17-54 kD, is far less permeable than other molecules similar in size,indicating that factors other than simple molecular weight areimportant. Thus, in one embodiment, IL-6, IL-1 β and some LPS areeffectively and efficiently removed by this system in high percentages.

[0069] Hemoconcentrator

[0070] One or more hemoconcentrators are used in several embodiments ofthe present invention. The hemoconcentrator 106 is constructed of ahollow cylinder formed of polycarbonate or similar material. Thecylinder is, in one embodiment, approximately 10 inches long and about1.5 inches in diameter. An inlet and an outlet of suitable configurationto be attached to conventional medical tubing are provided in caps andat opposite ends of the cylinder. The caps are typically threadedlyattached to the cylinder. In addition, at least one effluent or drainageport is provided adjacent one end of the cylinder. The interior of thecylinder is filled with filter material comprising polysulfone hollowfibers, has a surface area of between about 1.2 m² to about 2.4 m² witha pore size of about 70-90 kD and is capable of removing blood proteinsand cell mediators whose molecular weight is less than about 85 kD.Because the blood is diluted to about 5% to 20% hematocrit, the gellayer formed by the blood is not thick enough to substantially reducethe effective pore size of the hollow fibers, as it is in conventionalhemofiltration techniques. Here, it estimated that the pore size isreduced by about 5% to 20% by the gel layer formed, whereas intraditional hemofiltration techniques, the pore size is reducedsignificantly more.

[0071] In one embodiment, two hemoconcentrators connected in series, areused. Use of two or more hemoconcentrators in series is particularlyefficient at reconstituting blood at lower than about 10% hematocritback to whole blood hematocrit. Additionally, when running the system atslower flow rates (i.e. at lower than about 100 ml/min), the extrasurface area provided by two or more hemoconcentrators is helpful inpreventing clogging of the filter. Moreover, in some embodiments, aseries of hemoconcentrators is better able to share the load ofultrafiltrate removal without exceeding desired filtration fractions. Inone embodiment, two concentrator pumps are used to remove theultrafiltrate. A dual raceway pump can be used in accordance withseveral embodiments of the current invention. In one aspect of theinvention, each concentrator pump is controlled separately, allowingfurther optimization and control of filtration fraction for eachhemoconcentrator. One skilled in the art will understand that more thantwo hemoconcentrators can be used in accordance with embodiments of thisinvention.

[0072] In one embodiment, a hollow fiber or filter surface area of about1.2 m² to about 2.4 m² is used to provide sufficient area toreconstitute the diluted blood in volumes equivalent to those added tothe circuit. Typically, blood returning to a septic patient is notsubstantially diluted because the patient may experience secondarypulmonary dysfunction.

[0073] Ultraviolet Irradiation

[0074] In some embodiments of the present invention, it is advantageousto use UV irradiation to inactivate microorganisms. FIGS. 2-6 showseveral views of a UV irradiator and bag used in some embodiments of theinstant invention.

[0075] In one embodiment, shown in FIG. 2, the irradiator includes a bag204 and UV channel (grid lamp) 211 shaped in a serpentine path. Twoquartz plates 212 used to compress the blood within the bag are alsoprovided. A cross-sectional view 204 a of the UV bag 204 and an enlargedview thereof 204 b is shown in FIG. 2. A blood flow channel 205 is shownin the cross-sectional view 204 a. During treatment, the UV bag containsone or more of the following: plasma 206, red blood cells 207, whiteblood cells 208, platelets 209 and bacteria 210. In one embodiment, thebag 204 is disposable and made of a biocompatible ethylene vinyl acetate(“EVA”) material. In another embodiment, the bag is made of afluoropolymer. The bag is typically open at each end and with a smallinlet therethrough. In one embodiment, the bag 204, or fluid chamber, isapproximately 15 to 20 inches long and about 8 to 10 inches wide with afluid path having a width of about 0.75-1 inches. The inlet has aninside diameter of about {fraction (3/16)} inch and is about {fraction(1/2)} inch long. Any suitable length for secure connection to thetubing can be used. This design optimizes the appropriate amount ofturbulence to ensure bacterial reduction while preventing cellulardebris from building up on the surface of the UV bag. One advantage ofthis design is that it prevents cellular debris build-up on the surfaceof the bag which would otherwise occlude the transmission of the UV-Cand prevent adequate bacterial reduction.

[0076] FIGS. 3A-E show various views of one embodiment of the UV system.The assembly consists of a UV grid lamp 303 and lamp support structure301, comprising a lamp support 302. In one embodiment, the UV grid lamp303 is supported in the UV lamp holder by buss wire 317. Quartz glassplates 305 are affixed to each side of the UV lamp holder with frames306. A thermister 310 is held against the UV grid lamp 303 by a mountingblock 309 to sense lamp temperature during use. Screws 311, 312, and 313are provided as attachment means. Strain relief clamp 308 is provided toretain lamp wires. Hole 307 is provided as an alignment means. Hole 314is provided as an attachment means. At least one spring 316 and onescrew 315 is provided to hold the thermister mounting block 309 againstthe lamp 303 with spring force. An O-ring 304 is provided to seal the UVlamp 303 from any blood leakage in the event that irradiator bag leaks.

[0077] In one embodiment, the UV irradiator assembly is used toirradiate dilute extracorporeal blood with UV-C energy in the range ofabout 200-280 nm. In a preferred embodiment, UV-C light in the range of254 nm is used. An open view of the irradiator is shown in FIGS. 4 and5. In one embodiment, shown in FIG. 4, the assembly consists of a 200 WUV-C grid lamp 411 and lamp support structure 413, and two quartz glassplates (compression plates) to constrain the diluted blood in theirradiator bag to approximately 0.025″ thickness. At least one UV-Csensor 414 is also provided. UV sensors and temperature sensors are usedto optimize ultraviolet output of the bulb. In several embodiments, anoptical sensor 414 for monitoring ultraviolet light during irradiationis used. According to data received from the sensor, the dose orintensity of UV light is adjusted. The UV light can be adjusted manuallyor adjustment can be automated. In one arrangement, electrical feedbackcontrol is provided from the sensor to the UV irradiator, therebyeliminating the need for manual control of light intensity.

[0078] In several embodiments, a safety interlock switch is provided toprevent unwanted user exposure to UV-C when loading/unloading thedisposable set of materials. In one embodiment, the irradiator includesa conventional ultraviolet light source with a radiation wavelength ofabout 254 nm. One skilled in the art will understand that other suitablesources can also be used in accordance with several embodiments of thecurrent invention. The UV source is connected to a suitable power sourcevia a connector. The UV source is covered with a quartz plate which isused to compress the bag to allow maximum exposure of the bloodsolution. One skilled in the art will understand that plates made of anymaterial that permits transmission of UV-C light can also be used inaccordance with several embodiments of the present invention.

[0079]FIG. 5 also shows an irradiator in open position. In oneembodiment, compression plates are hingedly attached to each side of theUV lamp holder by links 519. Air flow from the cooling duct 524 is usedto keep the UV lamp at the proper temperature. A serpentine blood path525 positioned within the irradiator bag 521 allows diluted blood toflow past the UV grid lamp.

[0080] A closed view of the irradiator is shown in FIG. 6. In oneembodiment, the compression plates 618 are fastened to the UV lampholder by thumbscrews 620. Compression plates 618 include inner 618 aand outer 618 b plates. The compression of the irradiator bag is set bythe set screw 622. Lamp support structure is also shown 613.

[0081] In one embodiment, the UV assembly, including quartz plate, ismounted within an aluminum enclosure which is impermeable to UV light.In a preferred embodiment, the two quartz plates compress the bloodwithin the bag to approximately 0.006-0.1 inches in order to establish anarrow space for blood flow therethrough. In one embodiment, a bag isplaced on each side of the UV lamp. This configuration effectivelydoubles the UV-C exposure with a single grid lamp.

[0082] In one embodiment of the current invention, heparinized andpossibly anti-oxidant or pharmaceutically treated blood in theextracorporeal circuit shown in FIG. 1 enters the inlet and passesthrough the serpentine path while a dose of approximately 1-50 mW/cm2 ofUV-C, preferably 1-19 mW/cm2 of UV-C, more preferably 4-9 mW/cm2 of UV-C(the “effective” dose) is applied to the blood mixture. In oneembodiment, the irradiator bag is placed between two quartz plates thatcompress (when closed) the diluted blood to about 0.025 inches inthickness, thereby facilitating the anti-microbicidal effect of the UVirradiator which delivers 1-50 mW/cm² of energy at 254 nm, preferably2-20 mW/cm² of energy at 254 nm, more preferably 10-12 mW/cm² of energyat 254 nm.

[0083] Automation

[0084] In several embodiments, an on-line optical sensor for monitoringhematocrit during hemodialysis is used. These optical sensors arereported in the art (Jabara and Murta (1995), herein incorporated byreference). In this arrangement, electrical feedback control from such asensor to pump 114 would eliminate the need for manual control at thispoint of the system.

[0085] In one embodiment, an electronic weight scale, or load cell 160,shown in FIG. 1, is provided. The load cell is used to measure orquantify the volume or mass of diluent. In one embodiment, a straingauge beam-type load cell is used to measure the weight of the diluentbag. In one embodiment, the load cell is used to weigh the diluent bagcontinuously and control pump speeds. In one aspect, the load cellmaintains a constant diluent weight, thereby maintaining return patienthematocrit at the same value as input patient hematocrit. In oneembodiment, the diluent volume is kept constant at 750 ml in the diluentbag. One skilled in the art will appreciate that any given setpointvolume can be used.

[0086] Computer Hardware and Software

[0087] Conventional computer hardware and software can be used with theHemaCharge device for clinical trials. In one embodiment, the HemaChargesystem is a computer-controlled device running off-the-shelf (OTS)DasyLab® software under Windows® 98. FIG. 12 shows an overview of oneembodiment of the present invention.

[0088] In one embodiment, the hardware comprises an off-the-shelfPentium-based Advantech® computer with a color LCD display and touchscreen connected to an off-the-shelf DaqBook 200® data acquisition andcontrol system (Iotech Corporation). In one embodiment, the productiondevice uses custom hardware and software. This system interfaces topumps, clamps, ultraviolet lamp and transducers. In one embodiment, oneor more pressure transducers or temperature sensors located at variouspoints in the primary or secondary circuit are used as feedback for thesoftware to ensure safe and optimal operation. In one aspect of theinvention, the hardware includes an independent Watchdog Timer. If theOTS software or Windows 98 stops running, the Watchdog Timer is designedto turn off power to the lamp, pumps and clamps, which will stop flow,clamp blood lines and place the system into a safe mode. The clinicalprocedure would be stopped with a loss of approximately 250 ml ofextracorporeal blood in the circuit, in the event of a failure.

[0089] User Operation

[0090] In one embodiment, four basic modes of operation are provided:(1) setup mode, (2) prime mode, (3) run mode, and (4) shut down mode.

[0091] Setup mode is used for loading a disposable set of materials,including spiking user-supplied diluent bag. The disposable set ofmaterials includes one or more of the following: a hollow fiber filterused for hemoconcentrating dilute blood, one or two hollow fiber filtersfor cytokine removal, an irradiator bag assembly, and two additionalbags (one for priming and one for containing diluent). During this mode,all pumps, clamps and alarms are disabled. Message prompts direct userthrough disposable set loading, input of patient hematocrit and bloodvolume, and calibration of pressure sensors.

[0092] The user initiates prime mode by depressing the appropriate keyon the touch screen display, at which time both the primary and diluentcircuits are primed, and the diluent bag will be filled to the properlevel. Once filled, a heater warms the contents of the diluent bag tonormal body temperature. Once the circuit is primed, debubbled, and upto temperature, the clinician then pauses the system, and connects inletand outlet lines to the patient catheter. In some embodiments, a heateror heat exchanger is used to warm or cool at least some portion of theblood or diluent to between about 34° C. to about 42° C. In someinstances, a heat exchanger is used to warm or cool the bloodtemperature to body temperature prior to reintroduction into thepatient. In some embodiments, a heater is used to increase thetemperature of at least a portion of the blood by about 1° C. to about10° C.

[0093] Once priming is completed and patient is connected, the userinitiates run mode, at which time primary circuit priming volume (˜250ml) is displaced by patient blood, and infused into the patient. Duringnormal operation, patient blood is introduced to the device, diluted,irradiated, and hemoconcentrated back to the proper hematocrit beforebeing returned to the patient.

[0094] At the end of the procedure, in shut down mode, the user pausesthe system, disconnects the patient supply line and attaches it to thediluent bag. The user then resumes blood flow, displacing the remainingblood in the primary circuit with diluent, thereby returningextracorporeal blood to the patient. Pumps are stopped when diluent hasdisplaced the blood in the return line. At this time, the catheter isremoved from the patient and the disposable set of materials isdiscarded.

[0095] Bacterial Reduction and Cytokine Sieving

[0096] In several embodiments of the current invention, a system isprovided to reduce bacterial load in patient blood. In many embodiments,cytokines and other immune system mediators are removed. As used herein,the term “removed”, and any tense thereof, shall be given its ordinarymeaning, and shall also mean reduced in concentration, quantity and/orefficacy. FIG. 7 shows UV-C penetration as a function of hematocrit andblood thickness. FIG. 8 shows dilutional effect on bacterial reductionin vitro. FIG. 9 shows bacterial reduction data at various patienthematocrits in the HemaCharge system at 6 L blood volumes. FIG. 10 showsbacterial reduction data at 30% patient hematocrit at 3 L blood volumes.FIG. 11 shows cytokine sieving/reduction data in vitro at 6 L bloodvolumes. In one embodiment of the present invention, diluted bloodpasses through tubing to the bactericidal ultraviolet (UV) irradiationdevice, shown schematically in FIGS. 2A-D. Controlled in vitroexperiments have demonstrated that UV irradiation penetrates the bloodmore effectively when whole blood (26-55% hematocrit) is diluted to ahematocrit of about 5-20% (see FIG. 7) thus translating into a moreefficient microbicidal activity (see FIG. 8). Further, when dilutedblood is presented to the hemoconcentrator 106, target molecules aremore effectively removed by sieving. In many embodiments of the currentinvention, toxic targets, such as bacteria and immune system mediators,are removed from a patient's blood without using ultraviolet lightirradiation. In some of these embodiments, a series of hemoconcentratorsand filters are used to reduce pathological targets in blood. Immunesystem mediators, include, but are not limited to, inflammatorymediators. Inflammatory mediators include, but are not limited to, TNF,IL-1β, IL-6, IL-8, IL-10, IL-12, LPB, IFNγ, LIF, MIF, MCP-1, C3-a, C5-a,exotoxins and endotoxins. In one embodiment, the concentration of atleast one inflammatory mediator is reduced by about 75% in less thanabout 4 hours using embodiments of the current invention. In anotherembodiment, the concentration of TNF-α is reduced by about 50% in lessthan about 4 hours.

[0097] Vitamin Therapy

[0098] Vitamin therapy is used in several embodiments of the currentinvention as an adjunctive therapy. In several embodiments, a system andmethod of reducing toxins in a patient's blood using vitamin therapy isprovided. These vitamins include the free radical quenchers andantioxidants described below, and also include several vitamins whichexert their action by reducing the concentration of toxins, including,but not limited to bacteria, viruses, free radicals and inflammatorymediators, in the blood. In one embodiment, vitamins are added to theblood prior to, during and/or after treatment with theconcentrator/filter embodiments described herein. Vitamins areadministered directly to the patient and/or are added to the variouscomponents of the concentrator/filter embodiments, including, but notlimited to, the tubing, the pump, the filters and the diluent source sothat the blood can be exposed to the vitamins while being concentratedor filtered using this system. Antioxidants and free radical quenchersadministered in several embodiments of the current invention, include,but are not limited to, Zn, Cu, manganese, selenium, vitamin A, C, E, Bcomplex, K, P, lycopene, superoxide dismutase, co-enzyme Q10, catechins,polyphenols, flavanols, depsides (chlorogenic acid, coumaroylquinic acidand theogallin), quinic acids, carotenoids, thearubigens, theaflavin andtheaflavic acids are used to reduce bacterial load in blood processed byseveral embodiments of the current invention. In one embodiment, acombination of Vitamin A, C, E and zinc is used. In one embodiment,naturally-occurring and/or synthetic theaflavin is used. In oneembodiment, ethyl pyruvate, a chemical additive with anti-oxidantproperties, is used. One skilled in the art will be able to determinethe appropriate dose of antioxidants, to be administered. In oneembodiment, doses are adjusted per blood volume to yield maximum plasmaconcentration values (Cmax) of about 1 pg/ml plasma to about 1 mg/mlplasma per individual component. Preferably, doses to achieve Cmaxvalues of about 10 ng/ml to about 1000 ng/ml are provided. In oneembodiment, the following plasma concentrations are used: Vitamin B12 at0.2-0.5 mg/ml, Vitamin E at 0.13 IU/ml, Vitamin C at 0.16 mg/ml, VitaminP at 0.65 mg/ml, Vitamin A at 0.02 IU/ml and Vitamin K 0.003 mg/ml.

[0099] In one embodiment, one or more vitamins are added to the bloodwhile the blood is being processed through the system of the currentinvention. In other embodiments, patients are treated with a vitamincocktail prior to treatment using the present invention. In someembodiments, patients are given the vitamin cocktail after their bloodhas been treated with the present invention in order to maintain areduced cytokine and/or bacterial load. In some embodiments, vitamintherapy is administered in between treatments. Extracorporeal blood mayalso be treated at any time before, during or after treatment with thesystem of the current invention. In embodiments in which vitamin therapyis provided simultaneously with treatment by the system of the currentinvention, one or more vitamins are pre-mixed with the diluent. Inanother embodiment, a vitamin cocktail is added to the pump, so that thevitamins and blood and/or diluent mix with the vitamins duringprocessing. One of skill in the art will understand that vitamins can beadded at any stage and in any component of the current blood treatmentsystem.

[0100] In one embodiment, pharmacological therapy is administered insubstantially the same way as described above for vitamin therapy. Inone embodiment, insulin therapy is provided to facilitate cellularglucose entry for improved mitochondra performance. One skilled in theart will appreciate that other drugs which facilitate cellular glucoseentry and/or for improving mitochondria performance can also be used inaccordance with several embodiments of the current invention. In anotherembodiment, nitroglycerin is provided to improve microcirculation inorder to improve organ oxygenation. One skilled in the art willappreciate that other drugs which improve microcirculation can also beused.

[0101] In several embodiments, vitamin therapy is used in conjunctionwith a UV irradiator. In one embodiment, antioxidants and other freeradical quenchers are used to reduce free radicals which may be producedby the UV light and as a result of typical sepsis-induced cell damage.In some embodiments, the vitamins used to treat the blood to preventactivation of cells which initiate build-up on the surface of the UV bagand occlude the transmission of the ultraviolet light. One skilled inthe art will appreciate that pharmaceuticals, chemicals or other agentscan also be used instead of, or in addition to, the anti-oxidants andquenchers described herein. In one embodiment, the UV-C facilitates thepenetration of pharmaceutical agents into cells more effectively byactivating cell membranes to increase permeability.

EXAMPLES

[0102] The following Examples illustrate various embodiments of thepresent invention and are not intended in any way to limit theinvention.

Example 1 The HemaCharge Device

[0103] In one embodiment of the current invention, shown in FIG. 13, anembodiment referred to as “the HemaCharge device” is provided. In thisembodiment, the system comprises three pumps (blood pump 1302, diluentpump 1304, and hemoconcentrator pump 1306), an ultraviolet irradiatorlamp assembly 1308 and a load cell 1310 to maintain proper hemodilutionand hemoconcentration of patient blood. The user interface is a backlitLCD touch screen display 1312. The device also incorporates clamps, abubble detector, pressure sensors, temperature sensors, a UV sensor, aswell as visual and audible alarms for patient safety. A power supplymodule is provided containing an isolation transformer, a solid-stateelectronic ballast, and associated electronics to produce about 5-24 VDCto power the pumps, clamps, and sensors. A strain gauge beam type loadcell is provided to measure the weight of the diluent bag. A 70-90 kDpolysulfone hollow fiber filter 1314 used for hemoconcentrating diluteblood and two 10 kD polysulfone hollow fiber filters 1316 for cytokineremoval are also provided.

[0104] The UV irradiator assembly 1308 is used to irradiate diluteextracorporeal blood with 254 nm UV-C energy. The assembly consists of a200 W UVC grid lamp and lamp support structure, two quartz glass platesand compression plates to constrain the diluted blood in the irradiatorbag to approximately 0.025″ thickness, and UV-C and temperature sensorsto optimize ultraviolet output of the bulb. A safety interlock switch isprovided to prevent unwanted user exposure to UV-C whenloading/unloading the disposable set of materials.

[0105] The three pumps consist of a blood pump 1302 for pumping wholeblood from the patient to the irradiator, a diluent pump 1304 forintroducing diluent into the whole blood before the irradiator,resulting in hemodilution to about 10% HCT, and a concentrator pump 1306used to provide a transmembrane pressure across the 70-90 kD filter 1314for hemoconcentration before returning blood to the patient. Pumpcontrol is accomplished by using proportional-integral-differential(PID) feedback loops from encoders located on each pump motor, alongwith pump ratio parameters calculated from user input of HCT and bloodflow rate.

[0106] Three clamps are provided: one each on the patient inlet andoutlet lines for patient isolation and safety, and a third clamp toallow by-passing of the cytokine filter 1316 for discontinuance ofcytokine filtration. The bubble detector is located immediately beforethe patient return line clamp for protection against returning airemboli to the patient.

[0107] Five pressure sensors are used; one each on the patient inlet andreturn lines, one before the irradiator bag assembly inlet, one at thehemoconcentrator inlet, and one located between the hemoconcentratorultrafiltrate outlet and the concentrator pump 1306. The inlet pressuresensor can be used to determine maximum allowable blood flow rate basedon vascular access and catheter placement parameters; the patient returnline sensor can likewise indicate catheter placement issues on thereturn side, as well as provide a measure of safety against excessivereturn pressures. The sensor located before the irradiator bag assemblyprovides an indication of bag pressure and is used to prevent overpressurization of the irradiator bags. The sensors located at the inletand ultrafiltrate outlet of the hemoconcentrator 1306 as well as thepatient return sensor can be used together to determine hemoconcentratorTMP. TMP can be used to determine appropriate blood flow rates and todetermine adequate performance of the hemoconcentrator 1306. Visual andaudible alarms are provided for out-of-range pressures.

[0108] Temperature is sensed at one or more of the following locationsin the circuit: patient inlet and outlet, irradiator bag assembly outlet1308, and on the diluent bag. Additionally, the UV lamp temperature isalso monitored for optimization of UVC output. Sensors in theextracorporeal circuit are used to assure a safe blood temperaturethroughout the circuit. Visual and audible alarms are provided forout-of-range temperatures.

[0109] Computer hardware and software, described substantially as above,is used with the HemaCharge device.

[0110] In one aspect of the HemaCharge device, a disposable set ofmaterials is provided. The disposable set comprises a 70-90 kDpolysulfone hollow fiber filter 1314 used for hemoconcentrating diluteblood, one or two 10 kD polysulfone hollow fiber filters 1316 forcytokine removal, an EVA irradiator bag assembly, and two PVC bags; onefor priming and one for containing diluent. Although one skilled in theart will understand that several filters can be used in accordance withvarious embodiments of the present invention, polysulfone hemofiltersare particularly advantageous because of their biocompatibility andbecause they absorb serum factors associated with complement factor C3biexpression on neutrophils and monocytes. In some embodiments,electrostatically charged, melt-blown material, such as polypropylene,can be used. The disposable set also incorporates a bubble trap, twoinjection sites for administering medications, and the required tubinginterfaces for the pressure and temperature sensors. Catheters anddiluent for priming are user-supplied items. All tubing is PVC, anddisposable sets are tested for biocompatibility and sterility beforeinitiation of treatment.

Example 2 In Vitro Studies

[0111] Over one thousand in vitro experiments have been conducted todate using several embodiments of the present invention. Factorsinvestigated included appropriate UV transparent material, hematocrit ofblood for optimal UV absorption, ideal blood flow path for adequate UVexposure, ideal UV dosage, ideal pore size of hemofilters, ideal surfacearea of hemofilters, ideal blood model, development of porcine cytokineassays, various circuit coatings and optimal flow rates.

[0112]FIGS. 8-10 show data from bacterial reduction studies. In oneembodiment, a logarithmic base ten reduction (90%) of Staphylococcusaureus (ATCC 6538p) was provided within three hours and in someinstances a two logarithmic base ten (99%) reduction within six hours ofUV-C exposure. Staph. aureus was selected as the bacterial model becauseit is one of the most common organisms associated with sepsis andbecause it is considered one of the most difficult to kill. One skilledin the art will understand that other bacteria can also be effectivelyreduced in accordance with several embodiments of the current invention.FIG. 9 demonstrates a series of 36 bacterial reduction experimentsconducted at a blood volume of 6 liters. The maximum UV dosage was 16.14kJ. Patient blood flow rate was 100 ml/min. 31 UV experiments and 5controls were performed. FIG. 10 demonstrates a series of 8 bacterialreduction experiments conducted at a blood volume of 3 liters. Themaximum UV dosage was 12.90 kJ. Patient blood flow rate was 100 ml/min.5 UV experiments and 3 controls were performed.

[0113] These in vitro experiments were conducted with three or sixliters of fresh bovine whole blood anti-coagulated with EDTA. To allowfor the UV to penetrate the blood and to facilitate the efficientsieving of middle molecular weight molecules, the blood was diluted to10% prior to entering the irradiator and then re-concentrated to thestarting hematocrit via the 85 kD hemoconcentrators. Bovine bloodanti-coagulated with EDTA was chosen as the blood model because it is anindustry accepted standard for evaluating hemofilters and because it isless subject to daily variations. Each experiment used a breadboard—UVirradiator at a patient blood flow rate of 100 ml/min. Additionally,controls were conducted without the UV-C light to determine how thesystem and fresh blood affect the level of bacterial reduction alone. Asindicated in the graphs, the UV-C energy was responsible for the 90%reduction of bacteria. Other studies were conducted at various bloodvolumes, flow rates and patient hematocrits and resulted in at least a90% reduction in Staph. aureus.

[0114]FIG. 11 shows data from cytokine sieving, or reduction, studies.Typically, cytokine reduction studies have been conducted on TNF-α,IL-1β, and IL-6 because these cytokines have been well-established asmarkers for sepsis. Additionally, down-regulating the immune system, asopposed to suppressing it completely, may be important in treatment. A50-75% reduction in key inflammatory mediators can reverse theexaggerated immune response and allow the immune system to becomeeffective again. FIG. 11 shows several embodiments of the currentinvention provide at least a 50-75% clearance of all three targetmolecules within three hours. Cytokine studies were conducted asdescribed above for the bacterial reduction experiments Additionalstudies have been conducted at various blood volumes, flow rate andpatient hematocrits. One skilled in the art will understand that invarious embodiments of the current invention, the current system will beable to remove several cytokines and cell mediators, including, but notlimited to, TNF-α, IL-1β, IL-6, IL-10, IL-12, LPB, IFNγ, LIF, MIF,MCP-1, C3-a, C5-a, exotoxins and endotoxins.

Example 3 In Vivo Studies

[0115] Over eighty animal studies have been conducted in accordance withseveral embodiments of the current invention. Variables investigatedincluded appropriate animal models, effects of UV dosage, maintaining apig under anesthesia for up to 16 hours, ideal flow rates, variouscircuit coatings, various anticoagulants and various replacement fluids.The cell safety data represents 16 animal trials encompassing fourdifferent safety models: Sham, Tubing Control, UV Control andExperimental. All trials were conducted on 50-68 kg SPF Yorkshire pigsanesthetized and in recumbent position. Venous blood supply was obtainedby way of a femoral vein cut-down and blood pressure was monitored viathe femoral artery. Each subject was monitored for at least one weekpost-treatment. The following is a brief description of each model:

[0116] In the sham model, a 12 french double lumen catheter was placedin the femoral vein and the subject was monitored for six hours.

[0117] In the tubing sham model, the technique was similar to the shammodel, with the addition of a simple extracorporeal circuit composed ofdialysis tubing with an equivalent extracorporeal volume of the systemand one blood pump set to 100 ml/min.

[0118] In the control model, the breadboard system was run for six hoursat a patient blood flow rate of 100 ml/min without exposing the blood toUV-C.

[0119] In the experimental model, the complete breadboard system was runfor six hours at a patient blood flow rate of 100 ml/min while exposingthe blood to UV-C.

[0120] The data for all models demonstrated that the white blood cellcounts decreased during the first 60 minutes of the procedure, andtended to increase thereafter. The control model had the lowest six-hourwhite blood cell count; however, this sample was only slightly lowerthan the experimental model. Thus, the current system is the majorfactor affecting the white blood cell count, which is a typical responseto extracorporeal circulation. The UV-C was not a significant factor inthe decrease. The increase in post-treatment white blood cell counts isa typical response to anesthesia and extracorporeal devices. Ultimately,the one-week (168 hr) sample for all models demonstrated essentially thesame white blood cell counts, indicating that the effect of the circuitwas temporary.

[0121] The red blood cell counts remained relatively stable throughoutthe treatment and recovery periods of all models. Overall, the circuitand the UV-C did not have an effect on the red blood cell counts.

[0122] The platelet counts typically exhibited a downward trendthroughout the treatment period for the control and experimental models.The experimental model typically had the lowest overall six-hourplatelet count. This count, however, was well above the safety cut-offlevel of 50,000 platelets per deciliter. The decrease observed in bothmodels indicated that the system's circuit and the UV-C each had aneffect on the subject's platelet levels. All platelet counts for eachmodel increased to above-normal levels within 48 hours followingtreatment as a typical response to anesthesia and extracorporealdevices. Ultimately, the one-week (168 hr) sample for all modelsdemonstrates platelet counts within the normal range. This indicatesthat the effect of the circuit and UV-C are temporary. Other cell damagedata collected are described and discussed below.

[0123] A methemoglobin assay was used to determine the level of damageto the hemoglobin molecule. A value less than 2% of the totalconcentration of hemoglobin in the blood is considered normal. All thesamples were well within the normal range and did not significantlyincrease throughout the treatment. This indicates that the UV-C, at thegiven dosage, is not causing any significant damage to the hemoglobinmolecule.

[0124] A white blood cell viability dye exclusion assay was used todetermine whether a white blood cell is viable due to damages to the DNAand cell membrane. If a cell takes in the dye, that cell is considerednon-viable. Less than or equal to 10% overall reduction from thebaseline value is considered normal. All-of the samples for each modelwere within the normal range. This indicates that the circuit and UV-Cwere not causing any damage to the cells.

[0125] A red blood cell osmotic fragility assay was used to determineany cell membrane damage that could cause future lyses when returned tothe subject. Permeability of erythocyte cell membranes is a factor toconsider after UV irradiation. A sample of blood is mixed with 0.9%isotonic solution of saline and distilled water is added to the bloodmixture until lyses is observed. The results are represented as thesaline concentration at which the first cells begin to lyses (InitialOsmotic Fragility) and the saline concentration at which all of thecells are lysed (Complete Osmotic Fragility). The normal range forInitial Osmotic Fragility is 0.50-0.59% saline. The normal range forComplete Osmotic Fragility is ≦0.50% saline. All of the samples for eachmodel were within the normal range. This indicates that the circuit andUV-C were not causing any damage to the cells.

[0126] Platelet activation assays were used to determine the level ofplatelet assays are listed in order of platelet activation level:Platelet CD62P, Platelet Bound Fibrinogen, Monocyte-Platelet Aggregatesand Neutrophil-Platelet Aggregates. Samples for each assay were takenacross the circuit at the following locations: From Subject, Pre-UV,Post-UV and Post-Hemoconcentrators. For every assay, the level ofactivation increased as the cells moved through the circuit. In otherwords, diluting, irradiating and hemoconcentrating the blood had acontributing and cumulative effect on platelet activation. Inparticular, the Leukocyte-Platelet Aggregates at the six-hour samplewere up to levels seen in cardio-pulmonary bypass systems.

[0127] At the current dosage of UV-C, platelets were the only cells thatwere significantly affected. However, it is important to note that noneof the platelet levels from any of the safety models discussed abovewould have prompted a physician to supply replacement donor platelets toa human patient (i.e., less than about 50,000 platelets/dl).

[0128] While a number of preferred embodiments of the invention andvariations thereof have been described in detail, other modificationsand methods of use will be readily apparent to those of skill in theart. Accordingly, it should be understood that various applications,modifications and substitutions may be made of equivalents withoutdeparting from the spirit of the invention or the scope of the claims.

What is claimed is:
 1. A method for down-regulating a patient's immunesystem by removing one or more immune system mediators from thepatient's blood, comprising: removing at least a portion of thepatient's blood; diluting the blood with a diluent to provide dilutedblood, thereby reducing the hematocrit of said blood; concentrating thediluted blood using a membrane having a transmembrane pressure greaterthan 76 mmHg, thereby removing the diluent therefrom; filtering saiddiluted blood to remove one or more immune system mediators from saiddiluted blood, thereby producing treated blood; and returning thetreated blood to the patient.
 2. The method of claim 1, wherein the stepof filtering said diluted blood to remove one or more immune systemmediators comprises removing an inflammatory mediator.
 3. The method ofclaim 2, wherein the step of removing an inflammatory mediator.comprises reducing the concentration of at least one inflammatorymediator by about 75% in less than about 4 hours.
 4. The method of claim2, wherein the step of removing the inflammatory mediator comprisesremoving a inflammatory mediator selected from the group consisting ofone or more of the following: TNF-α, IL-1β, IL-6, IL-8, IL-10, IL-12,LPB, IFNγ, LIF, MIF, MCP-1, C3-a, C5-a, exotoxins and endotoxins.
 5. Themethod of claim 1, further comprising reducing the concentration ofTNF-α by about 50% in less than about 4 hours.
 6. The method of claim 1,wherein the step of filtering said diluted blood comprises filteringsaid diluted blood using at least two filters.
 7. The method of claim 6,wherein the step of filtering said diluted blood comprises filteringsaid diluted blood using a first filter having a porosity of about 70kilodaltons to about 90 kilodaltons.
 8. The method of claim 6, whereinthe step of filtering said diluted blood comprises filtering saiddiluted blood using a second filter having a porosity of about 10kilodaltons to about 30 kilodaltons.
 9. The method of claim 6, whereinthe step of filtering said diluted blood comprises filtering saiddiluted blood using two cytokine filters, each cytokine filter having aporosity of about 10-30 kilodaltons.
 10. The method of claim 1, whereinsaid concentrating step and said filtering step occur substantiallysimultaneously.
 11. The method of claim 1, further comprising returningthe diluent removed from the blood to a diluent source via a recyclepath.
 12. The method of claim 11, further comprising returning thediluent removed from the blood to a diluent source via a recycle pathusing a recycle path filter.
 13. The method of claim 12, furthercomprising using recycle path filter comprised of electrostaticallycharged, melt-blown material.
 14. The method of claim 1, furthercomprising an oxygenating the blood received from the patient.
 15. Thesystem of claim 1, further comprising heating at least a portion of theblood to about body temperature.
 16. The system of claim 1, furthercomprising cooling at least a portion of the blood to about bodytemperature.
 17. The system of claim 1, further comprising heating atleast a portion of the blood to between about 34° C. to about 42° C. 18.The system of claim 1, further comprising cooling at least a portion ofthe blood to between about 34° C. to about 42° C.
 19. The system ofclaim 1, further comprising changing the temperature of at least aportion of the blood by about 1° C. to about 10° C.
 20. The method ofclaim 1, further comprising providing at least one pump for moving saidblood or diluent.
 21. The method of claim 1, further comprisingtransporting said diluted blood at a flow rate of less than 400 ml/min.22. The method of claim 1, further comprising irradiating at least aportion of the diluted blood.
 23. The method of claim 22, wherein thestep of irradiating at least a portion of the diluted blood comprises:receiving blood from the patient; supplying a portion of the receivedblood to an irradiation device; and returning the remainder of thereceived blood to the patient.
 24. The method of claim 22, wherein thestep of irradiating at least a portion of the diluted blood comprises:providing a UV light source; providing a fluid chamber adjacent to saidUV light source, said fluid chamber confining the diluted blood to athin film for exposure to said UV light source; and irradiating at leasta portion of the diluted blood with said UV light source.
 25. The methodof claim 22, wherein the step of irradiating at least a portion of thediluted blood comprises delivering ultraviolet radiation to the dilutedblood in a dose ranging from about 2 mW/cm² to about 20 mW/cm².
 26. Themethod of claim 22, wherein the step of irradiating at least a portionof the diluted blood comprises delivering a dose of ultravioletradiation to the diluted blood sufficient to deliver an effective doseof about 1 mW/cm² to about 19 mW/cm² to said diluted blood.
 27. Thesystem of claim 24, wherein the step of providing a fluid chambercomprises providing a bag to contain the diluted blood, said bag havinga length in the range of about 15 inches to about 20 inches, a width inthe range of about 8 inches to about 10 inches, and a fluid path havinga width of about 0.75 inches to about 1 inch.
 28. The method of claim24, further comprising transporting at least a portion of the dilutedblood through a serpentine path during irradiation.
 29. The method ofclaim 1, wherein the step of concentrating the diluted blood comprisesproviding two hemoconcentrators connected in series.
 30. The method ofclaim 1, wherein the step of concentrating the diluted blood comprises:providing a hollow cylinder; and providing a central core formed ofhollow fibers axially disposed within said hollow cylinder.
 31. Thesystem of claim 30, wherein the step of providing a hollow cylindercomprises providing a hollow cylinder having a length of about 10 inchesand a diameter of about 1.5 inches.
 32. The system of claim 30, whereinthe step of providing a central core comprises providing a central corehaving a surface area in the range of between about 1.2 m² to about 2.4m².
 33. The method of claim 1, wherein returning the blood to thepatient further comprises providing tubing for the return path.
 34. Themethod of claim 1, further comprising providing a reservoir connected toreceive material filtered from the blood.
 35. The method of claim 1,further comprising providing an inlet monitoring means for monitoringthe pressure of the blood.
 36. The method of claim 1, wherein the stepof diluting the blood comprises reducing the hematocrit to about 5% toabout 20%.
 37. The method of claim 1, wherein the step of concentratingthe diluted blood using a membrane having a transmembrane pressuregreater than 76 mmHg comprises using a membrane having a transmembranepressure having a range of about 80 mmHg to about 85 mmHg.
 38. Themethod of claim 1, wherein the step of concentrating the diluted bloodusing a membrane having a transmembrane pressure greater than 76 mmHgcomprises using a membrane having a transmembrane pressure having arange of about 86 mmHg to about 95 mmHg.
 39. The method of claim 1,wherein the step of concentrating the diluted blood using a membranehaving a transmembrane pressure greater than 76 mmHg comprises using amembrane having a transmembrane pressure having a range of about 96 mmHgto about 105 mmHg.
 40. The method of claim 1, wherein the step ofconcentrating the diluted blood using a membrane having a transmembranepressure greater than 76 mmHg comprises using a membrane having atransmembrane pressure greater than about 105 mmHg.
 41. The method ofclaim 1, wherein removing at least a portion of the patient's bloodcomprises providing blood from a patient having an inflammatory disease.42. The method of claim 41, further comprising providing blood from apatient having an inflammatory disease, wherein said inflammatorydisease is selected from the group consisting of: sepsis, acute renalfailure, ischemic stroke, Sudeck's syndrome, chronic fatigue syndrome,heat stroke, Hodgkin's Disease, lupus, myocardial infarction, AIDS,viremia, HCV, HBV, tuberculosis, muscular dystrophy or multiplesclerosis, Acute Respiratory Distress Syndrome, and heart disease. 43.The method of claim 1, further comprising reducing free radicals in apatient's blood, comprising: exposing a first portion of the patient'sblood to ultraviolet light; and exposing a second portion of thepatient's blood to one or more free radical quenchers in a dosesufficient to reduce free radicals in said first portion of thepatient's blood.
 44. The method of claim 1, wherein the step of exposinga second portion of the patient's blood to one or more free radicalquenchers comprises exposing said second portion of the patient's bloodto one or more free radical quenchers selected from the group consistingof one or more of the following: Zn, Cu, manganese, selenium, vitamin A,C, E, B complex, K, P, lycopene, superoxide dismutase, co-enzyme Q10,catechins, polyphenols, flavanols, depsides, quinic acids, carotenoids,thearubigens, theaflavin, theaflavic acids and ethyl pyruvate.
 45. Themethod of claim 1, further comprising administering vitamin therapy to apatient's blood, comprising: exposing a portion of the patient's bloodto one or more vitamins in a dose sufficient to reduce one or moretoxins in said portion of the patient's blood.
 46. The method of claim45, wherein the step of exposing a portion of the patient's blood to oneor more vitamins comprises exposing a portion of the patient's blood toone or more antioxidants.
 47. A system for down-regulating a patient'simmune system by removing one or more immune system mediators from thepatient's blood, comprising: apparatus for removing blood from thepatient; a diluent source for supplying a diluent to the blood which hasbeen removed from the patient for the purpose of diluting the blood andreducing the hematocrit thereof; a first filter for receiving thediluted blood and extracting one or more immune system mediators anddiluent therefrom, said first filter having a transmembrane pressuregreater than 76 mmHg; a second filter for receiving the output from saidfirst filter including immune system mediators and diluent andextracting the immune system mediators therefrom; and a return pathwayfor returning a portion of the blood to the patient after the immunesystem mediators and diluent have been extracted therefrom by said firstfilter.
 48. The system of claim 47, further comprising an irradiationmeans for irradiating the diluted blood in order to inactivate one ormore toxins in the diluted blood.
 49. The system of claim 48, whereinsaid irradiation means comprises: a UV light source; and a fluid chamberadjacent to said UV light source, said fluid chamber confining saidfluid to a thin film for exposure to said UV light source.